This application relates to an anti-rotation feature between a gear cage, and a bearing sleeve in an air turbine starter turbine assembly.
Air turbine starter turbine assemblies are utilized to provide a starter function in gas turbine engines. In a typical air turbine starter turbine assembly, an auxiliary power unit (APU) is utilized to provide power prior to start-up of the main gas turbine engine. The compressed air from the APU is directed into an inlet of the air turbine starter turbine assembly, and drives a turbine rotor to rotate. The turbine rotor rotates, and serves as a starter motor for the main gas turbine engine.
A bearing sleeve surrounds a turbine shaft, and a plurality of bearings support the shaft within the bearing sleeve. During drive of the air turbine starter turbine assembly, there are rotational forces applied to the bearing sleeve, which could cause it to rotate. The bearing sleeve extends from a turbine rotor end adjacent to the turbine rotor, and to a gear end adjacent to a planetary gear.
In the prior art, a pin or other lock locks the bearing sleeve to a gear cage at the gear end of the bearing sleeve. With vibration and use, debris can be generated, and the debris can gain access into the interior of the air turbine starter turbine assembly.